The commercial use of genetically engineered crop species has caused concerns about the possible transfer of transgenes and traits encoded by transgenes from genetically modified plants (GM plants) into landraces, wild relatives or other non-GM plant varieties or related crop species (Ellstrand, N.C., 2001, Plant Physiol. 125, 1543-1545; Quist & Chapela, 2001, Nature, 414, 541-543), which could change the ecological balance in the affected ecosystems or lead to other, first of all, socioeconomic problems. Additionally, there is a certain fear that transgenes, especially antibiotic resistance genes used as transformation markers, can escape, through so-called horizontal transfer, into surrounding microorganisms (Chiter et al., 2000, FEBS Lett., 481, 164-168), thus modifying the microflora in an undesirable way.
Although many of these worries are not well justified scientifically (Christou, P., 2002, Transgenic Res., 11, iii-v), the creation of safe and controlled transgene management systems is highly desirable, as it might prevent potential problems in the future and shall help to protect the germplasm of existing plant species in the most efficient way. In addition, there are problems caused by contamination of organically grown crops or non-GM crops with transgenic cultivars. This has a serious impact on the marketing of transgenic as well as non-transgenic crops, an issue which cannot be ignored by producers.
Any transgenic material created by current technology and released into the environment has a potential of persisting there for a very long time. Common practice of plant genetic engineering is based on the use of expression cassettes and vectors that contain continuous coding sequence for the gene of interest. Such expression cassettes are integrated into a host chromosome and upon hybridization or another genetic information exchange between a GM plant and another organism, whether licit or illicit, the expression cassette is transmitted with a high probability to the progeny or another recipient as a functional transcriptional unit.
It is therefore an object of the invention to provide a process of producing a transgenic organism, notably plant organism, expressing a trait of interest, whereby distribution of said trait to progeny is controlled and occurs with low probability.
It is a further object of the invention to provide a controlled and biologically safe process of expressing a trait of interest in a multi-cellular organism or a cell thereof.